Electrophoretic display apparatus

• US 20040263701A1
• Filed: 04/20/2004
• Published: 12/30/2004
• Est. Priority Date: 04/21/2003
• Status: Abandoned Application

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Ukigaya, Nobutaka
• Application Number:
  US10/827,850
• Publication Number:
  US 20040263701A1
• Time in Patent Office: Days
• US Class Current: 349/36
• CPC Class Codes: G02F 1/167 by electrophoresis
• CPC Class Codes: G02F 1/16756 Insulating layers
• CPC Class Codes: G09G 2300/08 Active matrix structure, i.e. with use of active elements, inclusive of non-linear two terminal elements, in the pixels together with light emitting or modulating elements
• CPC Class Codes: G09G 2310/06 Details of flat display driving waveforms
• CPC Class Codes: G09G 2320/0204 Compensation of DC component across the pixels in flat panels
• CPC Class Codes: G09G 3/344 based on particles moving in a fluid or in a gas, e.g. electrophoretic devices electrophoretic devices per se G02F1/167

Abstract

An electrophoretic display apparatus includes a pair of substrates disposed opposite to each other, charged particles and an insulating liquid which are disposed in a spacing between the pair of substrates, a pair of electrodes for driving the charged particles, and drive means for applying to one of the pair of electrodes, a voltage for moving the charged particles, and applying to the other electrode, an AC voltage biased with a DC component. The AC voltage applied to the other electrode has a frequency which is higher than an upper limit of a frequency causing movement of the charged-particles and is lower than an upper limit of a frequency causing movement of ions contained in the insulating liquid. The ions do not remain on the surface of the substrate for a long time, thus causing no residual DC voltage.

Claims

1. An electrophoretic display apparatus, comprising:

a pair of substrates disposed opposite to each other,

charged particles and an Insulating liquid which are disposed in a spacing between the pair of substrates,

a pair of electrodes for driving said charged particles, and

drive means for applying to one of said pair of electrodes, a voltage for moving said charged particles, and applying to the other electrode, an AC voltage biased with a DC component for moving said charged particles,

wherein said AC voltage applied to the other electrode has a frequency which is higher than an upper limit of a frequency causing movement of said charged particles and is lower than an upper limit of a frequency causing movement of ions contained in said insulating liquid.

2. An apparatus according to claim 1, wherein the DC component of the AC voltage is set at a substantially center level of a modulation range of the voltage for moving said charged particles.

3. An apparatus according to claim 1, wherein the AC voltage has an amplitude which is larger than an amplitude of the voltage for moving said charged particles.

4. An apparatus according to claim 1, wherein the AC voltage has an amplitude which is smaller than an amplitude of the voltage for moving said charged particles.

5. An electrophoretic display apparatus, comprising:

a pair of substrates disposed opposite to each other,

charged particles and an insulating liquid which are disposed in a spacing between the pair of substrates,

a pair of electrodes for driving said charged particles,

an insulating layer for covering at least one of said electrodes, and

drive means for applying to one of said pair of electrodes, a voltage for moving said charged particles, and applying to the other electrode, an AC voltage biased with a DC component,

wherein said AC voltage applied to the other electrode has a frequency which is higher than an upper limit of a frequency causing movement of said charged particles and is lower than an upper limit of a frequency causing movement of electric charges contained in said insulating layer for covering said at least one electrode.